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Tag Archives: Epidemiology

The World Health Organization (WHO) has identified ten threats to global health in 2019.
These are:

Air pollution and climate change

Noncommunicable diseases

Global Influenza Pandemic

Fragile and vulnerable settings

Antimicrobial resistance

Ebola and other high-threat pathogens

Weak primary health care

Vaccine hesitancy

Dengue

HIV

We will consider each threat in turn:

Air Pollution and Climate change

Nine out of ten people breathe polluted air every day. In 2019, air pollution is considered by WHO as the greatest environmental risk to health.

Microscopic pollutants in the air can penetrate respiratory and circulatory systems, damaging the lungs, heart and brain, killing 7 million people prematurely every year from diseases such as cancer, stroke, heart and lung disease.

Around 90% of these deaths are in low- and middle-income countries, with high volumes of emissions from industry, transport and agriculture, as well as dirty cookstoves and fuels in homes.The primary cause of air pollution (burning fossil fuels) is also a major contributor to climate change, which impacts people’s health in different ways. Between 2030 and 2050, climate change is expected to cause 250 000 additional deaths per year, from malnutrition, malaria, diarrhoea and heat stress.

Noncommunicable Diseases

Noncommunicable diseases, such as diabetes, cancer and heart disease, are collectively responsible for over 70% of all deaths worldwide, or 41 million people. This includes 15 million people dying prematurely, aged between 30 and 69.

Over 85% of these premature deaths are in low- and middle-income countries. The rise of these diseases has been driven by five major risk factors:

tobacco use,

physical inactivity,

the harmful use of alcohol,

unhealthy diets and

air pollution.

These risk factors also exacerbate mental health issues, that may originate from an early age: half of all mental illness begins by the age of 14, but most cases go undetected and untreated – suicide is the second leading cause of death among 15-19 year-olds.

Global Influenza Pandemic

The world will face another influenza pandemic– the only thing we don’t know is when it will hit and how severe it will be. Global defences are only as effective as the weakest link in any country’s health emergency preparedness and response system.

Fragile and vulnerable settings

More than 1.6 billion people (22% of the global population) live in places where protracted crises (through a combination of challenges such as drought, famine, conflict, and population displacement) and weak health services leave them without access to basic care.

Fragile settings exist in almost all regions of the world, and these are where half of the key targets in the sustainable development goals, including on child and maternal health, remains unmet.

Antimicrobial resistance

The development of antibiotics, antivirals and antimalarials are some of modern medicine’s greatest successes. Now, time with these drugs is running out. Antimicrobial resistance – the ability of bacteria, parasites, viruses and fungi to resist these medicines – threatens to send us back to a time when we were unable to easily treat infections such as pneumonia, tuberculosis, gonorrhoea, and salmonellosis. The inability to prevent infections could seriously compromise surgery and procedures such as chemotherapy.

Resistance to tuberculosis drugs is a formidable obstacle to fighting a disease that causes around 10 million people to fall ill, and 1.6 million to die, every year. In 2017, around 600 000 cases of tuberculosis were resistant to rifampicin – the most effective first-line drug – and 82% of these people had multidrug-resistant tuberculosis.
Drug resistance is driven by the overuse of antimicrobials in people, but also in animals, especially those used for food production, as well as in the environment.

Ebola and other High-threat pathogens

In 2018, the Democratic Republic of the Congo saw two separate Ebola outbreaks, both of which spread to cities of more than 1 million people. One of the affected provinces is also in an active conflict zone.

This shows that the context in which an epidemic of a high-threat pathogen like Ebola erupts is critical – what happened in rural outbreaks in the past doesn’t always apply to densely populated urban areas or conflict-affected areas.

At a conference on Preparedness for Public Health Emergencies held last December, participants from the public health, animal health, transport and tourism sectors focused on the growing challenges of tackling outbreaks and health emergencies in urban areas. They called for WHO and partners to designate 2019 as a “Year of action on preparedness for health emergencies”.

WHO’s R&D Blueprint identifies diseases and pathogens that have potential to cause a public health emergency but lack effective treatments and vaccines. This watchlist for priority research and development includes

Ebola,

several other haemorrhagic fevers,

Zika,

Nipah,

Middle East respiratory syndrome coronavirus (MERS-CoV),

Severe Acute Respiratory Syndrome (SARS) and

disease X, which represents the need to prepare for an unknown pathogen that could cause a serious epidemic.

Weak Primary Health Care

Primary health care is usually the first point of contact people have with their health care system, and ideally should provide comprehensive, affordable, community-based care throughout life.

Primary health care can meet the majority of a person’s health needs of the course of their life. Health systems with strong primary health care are needed to achieve universal health coverage.

Yet many countries do not have adequate primary health care facilities. This neglect may be a lack of resources in low- or middle-income countries, but possibly also a focus in the past few decades on single disease programmes. In October 2018, WHO co-hosted a major global conference in Astana, Kazakhstan at which all countries committed to renew the commitment to primary health care made in the Alma-Ata declaration in 1978.

Vaccine Hesitancy

Vaccine hesitancy – the reluctance or refusal to vaccinate despite the availability of vaccines – threatens to reverse progress made in tackling vaccine-preventable diseases. Vaccination is one of the most cost-effective ways of avoiding disease – it currently prevents 2-3 million deaths a year, and a further 1.5 million could be avoided if global coverage of vaccinations improved.

Measles, for example, has seen a 30% increase in cases globally. The reasons for this rise are complex, and not all of these cases are due to vaccine hesitancy. However, some countries that were close to eliminating the disease have seen a resurgence.

The reasons why people choose not to vaccinate are complex; a vaccines advisory group to WHO identified

complacency,

inconvenience in accessing vaccines, and

lack of confidence

are key reasons underlying hesitancy.

Health workers, especially those in communities, remain the most trusted advisor and influencer of vaccination decisions, and they must be supported to provide trusted, credible information on vaccines.

Dengue

Dengue, a mosquito-borne disease that causes flu-like symptoms and can be lethal and kill up to 20% of those with severe dengue, has been a growing threat for decades.

A high number of cases occur in the rainy seasons of countries such as Bangladesh and India. Now, its season in these countries is lengthening significantly (in 2018, Bangladesh saw the highest number of deaths in almost two decades), and the disease is spreading to less tropical and more temperate countries such as Nepal, that have not traditionally seen the disease.

An estimated 40% of the world is at risk of dengue fever, and there are around 390 million infections a year.

HIV

The HIV epidemic continues to rage with nearly a million people every year dying of HIV/AIDS.

Since the beginning of the epidemic, more than 70 million people have acquired the infection, and about 35 million people have died. Today, around 37 million worldwide live with HIV.

Reaching people like sex workers, people in prison, men who have sex with men, or transgender people is hugely challenging. Often these groups are excluded from health services. A group increasingly affected by HIV are young girls and women (aged 15–24), who are particularly at high risk and account for 1 in 4 HIV infections in sub-Saharan Africa despite being only 10% of the population.